Mets pitcher Jacob deGrom looks up as he walks to...

Mets pitcher Jacob deGrom looks up as he walks to the dugout after the top of the sixth inning against the Phillies at Citi Field on Wednesday. Credit: Kathleen Malone-Van Dyke

Mets players and manager Mickey Callaway are painfully aware of the team’s lack of production for Jacob deGrom.

DeGrom threw 113 pitches in eight shutout innings Wednesday night against the Phillies at Citi Field, allowing five hits and a walk, striking out seven — and walking off the mound with yet another no-decision.

Afterward, as usual, he didn’t voice any frustration about the lack of support.

Third baseman Todd Frazier, however, said deGrom certainly has the right to vent.

“I told him, ‘You can get in my face every day of the week, every time this happens, and I’d have to take it,’ ’’ Frazier said before the Mets’ 5-4 loss to the Nationals on Thursday night at Citi Field. “Because we are not giving him the support he needs, and for him to keep going out and not say boo about [anything] and keep working the way he works, it’s great to play behind him.”

DeGrom entered Thursday with the worst run support in baseball for starters throwing at least 120 innings (3.79 runs per start). In deGrom’s last 13 starts, the Mets averaged 2.77 runs, and if you take out a 12-run game against the Rockies, the average drops to 2.0.

Because of the lack of run support, deGrom has a 5-4 record with 10 no-decisions despite leading the majors with a 1.68 ERA and ranking second in WHIP (0.97), strikeouts (149) and innings pitched (123 1⁄3).

DeGrom has a 1.44 ERA in those 10 no-decisions, including a 0.55 ERA in his last eight no-decisions (three earned runs allowed in 49 innings).

Though the offense continues to perform poorly with deGrom on the mound, Callaway continues to be impressed by how he focuses and produces without showing frustration.

With a career ERA of 2.78, DeGrom has had dominant stretches throughout his Mets tenure, and Callaway thinks — in a way — that his need to keep opponents off the scoreboard because of the lack of support may have had a hand in his career year.

“Maybe it’s because we haven’t been scoring runs and he doesn’t want to lose,” Callaway said. “There could be something to that.”

The players certainly are aware of their lack of scoring for deGrom, even if they aren’t exactly sure of the reason.

“We certainly haven’t done any hitting on his starts, unfortunately,” catcher Devin Mesoraco said. “I’m not sure what the answer is, but hopefully that trend won’t continue.”

Could it be the hitters are actually putting more pressure on themselves during deGrom’s outings?

“Could be,” Frazier said. “You want to do that much better for the guy because you know how good he can be and we want him to win a Cy Young Award because he deserves it right now. Everybody’s going to yell about wins and losses and all that, but the way he throws, how dominant he has been, going seven, eight innings giving up one run or less, it’s just unbelievable.”

DeGrom’s 1.678 ERA (carried out to an extra decimal place) is the second lowest entering the All-Star break in franchise history behind Dwight Gooden, who had a 1.677 ERA in 1985. He’s allowed one run or fewer in 14 of his 19 starts this season and in 57 of his 125 career starts (45.6 percent).

But he hasn’t called out his teammates. He just continues to do his part.

“When I’m out there, I try to think it’s 0-0 the whole time,” deGrom said . . . “I think that’s just the mindset I’ve had since I started pitching. I don’t like giving up runs, I don’t want to and I go out there and try not to.”

“How good he’s done, how little we’ve given him, it’s tough,” Frazier said. “I don’t know how he does it because you have to come out to the ballpark every day you’re pitching and give your best shot, and he’s been doing that the whole first half of the season knowing that we haven’t given him many runs, and for him to keep doing that, that’s the sign of a true pro, a dominant pitcher, and I think any team in this world would take him for sure.”